JPH05267854A - Ceramic multilayer circuit board and manufacture thereof - Google Patents

Abstract

PURPOSE:To easily obtain a ceramic multilayer circuit board in which an accurately trimmed resistor is formed as an inner layer by providing the trimmed resistor in the inner layer interposed between a plurality of ceramic boards. CONSTITUTION:A plurality of alumina boards are prepared, through holes 2 are formed at the respective boards, and then Ag/Pd paste is filled in the holes 2 by a screen printing method. Then, a conductor wiring pattern 3 is printed, dried, baked, then a resistor 4 is printed, baked, and trimmed to form a resistor 4 having a target resistance. Thereafter, glass 5 for adhering the boards to each other is printed except the upper part of the resistor 4, conductor protrusions 6 are formed, the boards 1 are superposed to each other, the glass paste 5 is melted to adhere the boards to each other, and the boards are electrically conducted through the protrusions 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic multilayer wiring board used for electronic equipment and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing a ceramic multilayer wiring board, (1) a green sheet having an alumina purity of 92 to 95%,
After making holes using a die, etc., print through-hole conductors and wiring with a conductor paste such as W and Mo, stack green sheets of each layer, and press-bond them to 1500-1600.
Method for obtaining a ceramic multilayer wiring board by firing in an atmosphere of H2 + N2 + steam at ℃ (green sheet lamination method, conventional type) To 800 to 900 ° C., a green sheet that can be fired at a relatively low temperature is prepared, a conductor is formed and pressure-bonded in the same manner as in (1) above, and fired in an atmosphere suitable for the conductor (Ag / P
There is a method (green sheet lamination method, low temperature firing type) of obtaining a ceramic multilayer wiring substrate by using air for d and Au and N2 for Cu.

[0003]

However, in the above method (1), there is no material that can be used as the resistor of the inner layer because of the high firing temperature and the use of a reducing atmosphere. Further, in the method (2), a thick film resistor having ruthenium oxide as a main conductive component, which has been conventionally used for an alumina substrate, can be used. However, even in this method, all pastes are printed. Since the green sheet is pressure-bonded and baked after being dried, there is a large variation in the resistance value due to the mutual diffusion of the resistor and the substrate component, and a laser that is usually used as a method for adjusting the resistance value of thick film resistors. The trimming technology could not be used, and a resistor with sufficient accuracy for practical use could not be obtained.

The present invention solves the problem in the prior art that a practically usable resistor cannot be formed in the inner layer of the ceramic multilayer wiring board as described above, and the resistor trimmed with high precision is formed into the inner layer. It is an object of the present invention to provide a ceramic multilayer wiring board and a manufacturing method thereof.

[0005]

In order to achieve the above object, a method for manufacturing a ceramic multilayer wiring board according to the present invention comprises a step of printing wiring patterns and resistors on a plurality of fired ceramic substrates and firing them. A step of trimming the resistor, and a step of printing glass for joining the ceramic substrates together on the ceramic substrate except for the electrical connection between the resistor and the ceramic substrate, The method is characterized by including a step of printing a conductor protrusion on the electrical connection portion, a debinding processing step, and a step of stacking and firing the plurality of ceramic substrates.

The ceramic multilayer wiring board of the present invention is characterized in that an inner layer sandwiched between a plurality of ceramic boards is provided with trimmed resistors.
It is preferable that glass for joining the plurality of ceramic substrates is sandwiched in a region of the inner layer sandwiched between the plurality of ceramic substrates except the region where the resistor is formed.

[0007]

In the present invention, by using a pre-fired substrate as an individual inner layer substrate,
Trimming is possible. Furthermore, by not printing the bonding glass on the resistor, the interaction between the resistor and the bonding glass can be avoided, and the excellent resistance with the same characteristics as when forming on a normal alumina ceramic substrate. A ceramic multilayer substrate with a body can be obtained.

[0008]

EXAMPLE An example of a manufacturing process of a ceramic multilayer wiring board having a resistor of 150Ω in an inner layer will be described below with reference to the drawings. Thickness 0.1mm, external shape 50.8 × 50.8
A plurality of mm alumina substrates 1 are prepared (FIG. 1A),
A through hole 2 having a diameter of 0.1 mm was processed on this alumina substrate 1 by a laser processing machine (FIG. 1 (b)). Next, Ag / Pd paste 6502 manufactured by DuPont is filled in the through holes by a screen printing method (FIG. 1C), and subsequently, a conductor wiring pattern is printed by a screen printing method and dried.
Firing was performed at a profile of 50 ° C. for 10 minutes and a total of 1 hour (FIG. 1 (d)). The same applies to the following firing and joining conditions. Maximum temperature is 150 ° C for 5 minutes. Keep total 15
Minutes (the same applies to the following drying conditions). Next, the resistor 4 was printed and fired (FIG. 1E). Here, resistor 4
As the resistor, a resistor 6820 (100Ω / □) manufactured by DuPont was used. Preliminary experiments show that the resistance value drifts by 21% due to the heat treatment process of debinding and joining, so trimming was performed with a target value of 124Ω to form trimmed resistor 4 ′ (FIG. 1).
(F)).

After trimming, the glass 5 for adhering the substrates to each other was printed except for the upper portion of the resistor 4'and the conductive protrusions to be printed thereafter (FIG. 2 (g)).
As the glass, 1129TC manufactured by NFE was used. Next, a conductive paste 6502 manufactured by DuPont was used to print and dry the conductive protrusions 6 for establishing electrical conduction between the substrates (FIG. 2 (h)). Next, a heat treatment for debinding is performed under the conditions of a maximum temperature of 500 ° C., keeping for 10 minutes, and total time of 1 hour, and the substrates of the respective layers are superposed and bonded with each other while applying a load of 1 kg. The substrates were melted and adhered to each other, and the conductor protrusions 6 were sintered to achieve electrical conduction between the substrates (FIG. 2).
(I)). When the resistance value of the internal resistor was measured using the terminal drawn out on the surface of the multilayer board, it was 156Ω.
Therefore, a resistor having an accuracy of 4% was obtained with respect to the target value of 150Ω.

[0010]

As described above, according to the present invention, the ceramic layer wiring board on which the highly accurate inner layer resistor is mounted is constructed.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a ceramic multilayer wiring board according to an embodiment of the present invention.

FIG. 2 is a diagram showing a manufacturing process of a ceramic multilayer wiring board according to an embodiment of the present invention.

[Explanation of symbols]

1 Fired Ceramic Substrate 2 Through Hole 3 Conductor Wiring Pattern 4 Resistor 4'Resistor after Trimming 5 Glass 6 Conductor Protrusion

Claims (3)

[Claims] 1. A ceramic multi-layer wiring board comprising an inner layer sandwiched between a plurality of ceramic boards and trimmed resistors. 2. The glass for joining the plurality of ceramic substrates is sandwiched between the regions of the inner layer sandwiched between the plurality of ceramic substrates except the region where the resistor is formed. The ceramic multilayer wiring board according to claim 1. 3. A plurality of fired ceramic substrates,
A step of printing a wiring pattern and a resistor and baking the same; a step of trimming the resistor; and a glass for joining the ceramic substrates together on the ceramic substrate, an electrical connection between the resistor and the ceramic substrate. The step of printing without the electrical connection portion, the step of printing a conductive protrusion on the electrical connection portion, the step of removing the binder, and the step of firing the plurality of ceramic substrates by superposing them on each other. A method for manufacturing a ceramic multilayer wiring board, comprising: